I had one such booking... Of course missing in the system... After contacting Marriott by email it finally booked.... using new rate...
When I argue with them they told me "under the new rule you get more points", then I did a calculation to prove that they are wrong after taking into account the old Platinum welcome gift... Not to mention that my status was Platinum 75 but only a mere Platinum Elite now (yes they still not fixing this...)... End up they used the new rate for Platinum Premier Elite to calculate my points entitlement but didn't give me the 1000 points welcome gift.... Nevertheless it's still a few hundred points more than calculated using the old system so I'll let it go...
But until they fix my status (PPE v.s. PE), I won't make any revenue stay with any of the Marriott properties to further complicate my issue...